// Copyright 2012-present Oliver Eilhard. All rights reserved.
// Use of this source code is governed by a MIT-license.
// See http://olivere.mit-license.org/license.txt for details.

package helper

import "gitee.com/zackeus/go-boot/tools/jsonx"

// PrefixQuery matches documents that have fields containing terms
// with a specified prefix (not analyzed).
//
// For more details, see
// https://www.elastic.co/guide/en/elasticsearch/reference/7.0/query-dsl-prefix-query.html
type PrefixQuery struct {
	name            string
	prefix          string
	boost           *float64
	rewrite         string
	caseInsensitive *bool
	queryName       string
}

// NewPrefixQuery creates and initializes a new PrefixQuery.
func NewPrefixQuery(name string, prefix string) *PrefixQuery {
	return &PrefixQuery{name: name, prefix: prefix}
}

// Boost sets the boost for this query.
func (q *PrefixQuery) Boost(boost float64) *PrefixQuery {
	q.boost = &boost
	return q
}

func (q *PrefixQuery) Rewrite(rewrite string) *PrefixQuery {
	q.rewrite = rewrite
	return q
}

func (q *PrefixQuery) CaseInsensitive(caseInsensitive bool) *PrefixQuery {
	q.caseInsensitive = &caseInsensitive
	return q
}

// QueryName sets the query name for the filter that can be used when
// searching for matched_filters per hit.
func (q *PrefixQuery) QueryName(queryName string) *PrefixQuery {
	q.queryName = queryName
	return q
}

// Source returns JSON for the query.
func (q *PrefixQuery) Source() (interface{}, error) {
	source := make(map[string]interface{})
	qs := make(map[string]interface{})
	source["prefix"] = qs

	if q.boost == nil && q.rewrite == "" && q.queryName == "" && q.caseInsensitive == nil {
		qs[q.name] = q.prefix
	} else {
		subQuery := make(map[string]interface{})
		subQuery["value"] = q.prefix
		if q.boost != nil {
			subQuery["boost"] = *q.boost
		}
		if q.rewrite != "" {
			subQuery["rewrite"] = q.rewrite
		}
		if q.caseInsensitive != nil {
			subQuery["case_insensitive"] = *q.caseInsensitive
		}
		if q.queryName != "" {
			subQuery["_name"] = q.queryName
		}
		qs[q.name] = subQuery
	}

	return source, nil
}

func (q *PrefixQuery) Build() (string, error) {
	source, err := q.Source()
	if err != nil {
		return "", err
	}

	qs := make(map[string]interface{})
	qs["query"] = source

	s, err := jsonx.MarshalToString(qs)
	if err != nil {
		return "", err
	}
	return s, nil
}
